The most appropriate first-line imaging modality to detect adrenal metastasis due to bronchogenic carcinoma is:
Which of the following conditions characteristically causes bilateral hypertranslucency of lung fields on chest X-ray?
Which of the following is not typically seen on a chest X-ray in pulmonary artery hypertension?
Investigation of choice for intramedullary SOL is -
Popcorn calcification is seen in:
"Sunray appearance" on X-rays is suggestive of:
Step ladder pattern of gas shadow is seen in
Which of the following conditions can cause periosteal reactions?
The longest half life is that of:
NEET-PG 2012 - Radiology NEET-PG Practice Questions and MCQs
Question 21: The most appropriate first-line imaging modality to detect adrenal metastasis due to bronchogenic carcinoma is:
- A. PET scan
- B. MRI of the abdomen
- C. Adrenal radionuclide scan
- D. Contrast Enhanced CT abdomen (Correct Answer)
Explanation: **Contrast Enhanced CT abdomen** - **Contrast-enhanced CT abdomen** is generally considered the most sensitive and cost-effective imaging modality for detecting **adrenal metastases**. - It allows for detailed visualization of adrenal gland morphology, including size, shape, and enhancement patterns, which can help differentiate benign from malignant lesions. *PET scan* - While **PET (Positron Emission Tomography) scans** are highly sensitive for detecting metabolically active metastatic disease, they are often used as a secondary imaging modality to characterize indeterminate lesions found on CT or MRI. - **PET scans** can have false positives in benign adrenal tumors (e.g., adenomas rich in fat) and are less readily available or higher in cost for initial screening compared to CT. *MRI of the abdomen* - **MRI of the abdomen** can be very useful for further characterization of adrenal masses, especially for distinguishing between lipid-rich adenomas and metastases. - However, for initial detection, especially in the context of screening for distant metastases from bronchogenic carcinoma, **CT is generally preferred due to its wider availability, speed, and lower cost**. *Adrenal radionuclide scan* - **Adrenal radionuclide scans** (e.g., using MIBG or iodocholesterol) are primarily used for functional imaging of adrenal glands, typically to detect specific types of tumors like pheochromocytomas or aldosteronomas. - These scans are **not sensitive for detecting adrenal metastases** from bronchogenic carcinoma, as the metastatic lesions do not typically exhibit the specific uptake patterns targeted by these radiotracers.
Question 22: Which of the following conditions characteristically causes bilateral hypertranslucency of lung fields on chest X-ray?
- A. Mcleod syndrome
- B. Poland syndrome
- C. Emphysema (Correct Answer)
- D. Pneumothorax
Explanation: ***Correct: Emphysema*** - **Emphysema** causes destruction of alveolar walls, leading to enlarged air spaces and **air trapping**, making both lungs appear hypertranslucent on X-ray - This **bilateral hypertranslucency** is due to reduced lung tissue density, decreased vascular markings, and increased air volume - Classic radiographic features include flattened diaphragms, increased retrosternal space, and hyperlucent lung fields *Incorrect: Mcleod syndrome* - Also known as **Swyer–James–MacLeod syndrome**, this condition causes **unilateral** lung or lobe hyperlucency due to post-infectious obliterative bronchiolitis - The key differentiating feature is that it's **unilateral**, whereas the question asks for bilateral hypertranslucency - Affected lung shows air trapping on expiratory films *Incorrect: Pneumothorax* - A **pneumothorax** presents as a **unilateral** or focal hypertranslucent area due to air in the pleural space - Characterized by **absence of lung markings** beyond the visceral pleural line and associated lung collapse - This is a pleural space abnormality, not a bilateral parenchymal lung disease *Incorrect: Poland syndrome* - **Poland syndrome** is a congenital condition with absence or underdevelopment of the pectoralis major muscle - Can lead to **unilateral** apparent hyperlucency on the affected side due to missing chest wall muscle - This is a **chest wall anomaly**, not a parenchymal lung disease causing bilateral hypertranslucency
Question 23: Which of the following is not typically seen on a chest X-ray in pulmonary artery hypertension?
- A. Enlargement of central arteries
- B. Peripheral pruning
- C. Narrowing of central arteries (Correct Answer)
- D. None of the options
Explanation: ***Narrowing of central arteries*** - **Pulmonary artery hypertension** is characterized by the **enlargement of the central pulmonary arteries** due to increased pressure. - **Narrowing of central arteries** would contradict the hemodynamic changes seen in pulmonary hypertension. - This is the finding that is **NOT typically seen**, making this the correct answer. *Enlargement of central arteries* - This is a **hallmark radiographic finding** in pulmonary hypertension, reflecting the **dilatation of the main and proximal pulmonary arteries** due to increased pressure. - The **pulmonary artery segment becomes prominent**, often appearing convex on the left heart border. *Peripheral pruning* - This refers to the **abrupt tapering and loss of peripheral pulmonary vascular markings**, indicating reduced blood flow to the distal lung parenchyma. - It is a **common finding in advanced pulmonary hypertension**, as the distal vessels constrict and become obliterated. *None of the options* - This is incorrect since **narrowing of central arteries** is clearly not a typical finding in pulmonary hypertension.
Question 24: Investigation of choice for intramedullary SOL is -
- A. MRI (Correct Answer)
- B. USG
- C. CT
- D. X-ray
Explanation: ***MRI*** - **Magnetic Resonance Imaging (MRI)** is the investigation of choice for intramedullary lesions due to its superior **soft tissue contrast** and ability to visualize the **spinal cord** parenchyma. - It provides detailed information on lesion size, location, and internal characteristics, which is crucial for diagnosis and surgical planning. *USG* - **Ultrasound (USG)** has limited utility for intramedullary lesions as a primary diagnostic tool because **bone impedes sound waves**, making it difficult to visualize structures within the spinal canal. - It might be used for neonatal spinal screening or intraoperative guidance, but not for definitive diagnosis of intramedullary lesions in adults. *CT* - **Computed Tomography (CT)** excels at visualizing **bone structures** and calcifications, but it provides less detailed information about soft tissue elements like the spinal cord compared to MRI. - While it can identify bony changes associated with intramedullary lesions, it is not the preferred initial imaging modality for characterizing the lesion itself. *X-ray* - **X-rays** provide basic imaging of bone but offer essentially **no visualization of soft tissues** such as the spinal cord or intramedullary lesions. - They are primarily used to identify gross bony abnormalities like fractures or severe degenerative changes, not for subtle intraspinal pathologies.
Question 25: Popcorn calcification is seen in:
- A. Pulmonary hamartoma (Correct Answer)
- B. Bronchogenic carcinoma
- C. Tuberculosis
- D. Pulmonary metastases
Explanation: ***Pulmonary hamartoma*** - **Popcorn calcification** is a pathognomonic radiographic finding highly suggestive of **pulmonary hamartoma**, a **benign tumor** composed of cartilage, fat, and connective tissue - This characteristic calcification pattern is due to the presence of **chondroid (cartilaginous) tissue** within the lesion - Appears as coarse, irregular calcifications resembling popcorn on chest X-ray or CT scan *Bronchogenic carcinoma* - Malignant lung lesions typically show **irregular, spiculated, or ill-defined margins** and tend to grow rapidly - While calcification can occur in some lung malignancies, it usually appears as **eccentric, stippled, or amorphous** rather than the distinctive popcorn pattern - Popcorn calcification is not a feature of primary lung cancers *Tuberculosis* - **Granulomatous infections** such as tuberculosis often lead to calcification, but it usually presents as **laminated, clustered, or target-like patterns** in lymph nodes or within granulomas (Ghon lesion, Ranke complex) - **Popcorn calcification** is not a typical feature of active or healed tuberculous lesions *Pulmonary metastases* - **Metastatic lesions** are generally not calcified, although a few primary tumors (e.g., mucinous adenocarcinoma, osteosarcoma, chondrosarcoma) can metastasize as calcified nodules - When calcification is present in metastases, it is rarely in the specific **popcorn pattern** and is usually diffuse, punctate, or amorphous
Question 26: "Sunray appearance" on X-rays is suggestive of:
- A. A metastatic tumour in the bone
- B. An Osteogenic sarcoma (Correct Answer)
- C. An Ewing's sarcoma
- D. A type of bone cancer that can show various radiographic appearances
Explanation: ***An Osteogenic sarcoma*** - The **"sunray appearance" (or sunburst)** on X-rays is a classic radiographic finding pathognomonic for **osteosarcoma**, especially in adults and adolescents. - This appearance is due to the **periosteal new bone formation** that grows perpendicular to the bone surface, creating a radiating spicule pattern. *A type of bone cancer that can show various radiographic appearances* - While true that bone cancers can show various appearances, the "sunray appearance" is specific enough to strongly point to a particular type, rather than just a general category. - This option is too broad and does not provide the most precise diagnosis indicated by the specific radiographic sign. *A metastatic tumour in the bone* - Metastatic bone lesions typically present with **lytic (bone destruction)** or **blastic (bone formation)** patterns, or a mixed pattern, but rarely produce the periosteal "sunray" appearance. - The characteristic radiographic finding for metastasis would often involve multiple lesions and different periosteal reactions, such as an **onion skin appearance** in some aggressive cases, but not typically sunray. *An Ewing's sarcoma* - Ewing's sarcoma commonly presents with an **"onion skin" periosteal reaction** due to multiple layers of new bone formation. - While both are primary bone tumors, the radiographic findings are distinctly different, allowing for differentiation.
Question 27: Step ladder pattern of gas shadow is seen in
- A. Intestinal obstruction (Correct Answer)
- B. Gastric outlet obstruction
- C. Duodenal obstruction
- D. Sigmoid volvulus
Explanation: ***Intestinal obstruction*** - A **step-ladder pattern** of gas shadows is a classic radiological sign seen in **small bowel obstruction** due to dilated, fluid-filled loops of small bowel stacked on top of each other. - This pattern results from the accumulation of gas and fluid proximal to the obstruction, causing dilated bowel loops to arrange horizontally. *Gastric outlet obstruction* - This condition primarily results in a **dilated stomach** with fluid and gas, not typically a step-ladder pattern in the small bowel. - Vomiting is usually a prominent symptom, and imaging would show a large fluid-filled stomach. *Duodenal obstruction* - Causes dilatation of the stomach and duodenum, leading to a "**double-bubble sign**" (dilated stomach and proximal duodenum). - It does not typically produce the extensive, stacked small bowel loops seen in a step-ladder pattern. *Sigmoid volvulus* - Characterized by a distinctive large, dilated loop of sigmoid colon, often described as a "**coffee bean sign**" or an **inverted U-shape**. - This is a large bowel obstruction and does not typically present with a step-ladder pattern of small bowel gas.
Question 28: Which of the following conditions can cause periosteal reactions?
- A. All of the options (Correct Answer)
- B. Osteomyelitis
- C. Syphilis
- D. Tumor
Explanation: ***All of the options*** - **Periosteal reactions** are non-specific findings that indicate periosteal irritation or inflammation, which can be caused by a wide range of pathologies including infection, neoplasia, and trauma. - This option correctly encompasses the various causes listed in the other choices, making it the most accurate answer. *Osteomyelitis* - **Osteomyelitis**, an infection of the bone, can cause inflammation of the surrounding periosteum, leading to periosteal new bone formation. - The type of periosteal reaction can vary, from **lamellated** to **solid**, depending on the chronicity and aggressiveness of the infection. *Syphilis* - **Congenital syphilis** and tertiary acquired syphilis can lead to significant bone involvement, including **periostitis**, which manifests as periosteal reactions. - The classic appearance in children with congenital syphilis is a **wavy** or **irregular cortical thickening** due to widespread periostitis. *Tumor* - Both **primary bone tumors** (e.g., osteosarcoma, Ewing's sarcoma) and **metastatic lesions** can elicit a periosteal response as they invade or irritate the periosteum. - The periosteal reaction in tumors can present as aggressive patterns like a **sunburst** or **Codman's triangle**, indicating rapid bone destruction and new bone formation.
Question 29: The longest half life is that of:
- A. Radon
- B. Uranium (Correct Answer)
- C. Cesium
- D. Radium
Explanation: ***Uranium*** - **Uranium-238**, a common isotope, has an incredibly long half-life of approximately **4.468 billion years**, which is comparable to the age of the Earth. - This extremely long half-life is due to its slow **alpha decay**, making it a very stable radioactive element. *Radon* - **Radon-222** has a relatively short half-life of about **3.8 days**. - Its short half-life makes it a significant indoor air pollutant as it rapidly decays into other radioactive isotopes. *Cesium* - **Cesium-137**, a product of nuclear fission, has a half-life of approximately **30 years**. - While longer than radon, its half-life is much shorter compared to uranium, meaning it decays significantly faster. *Radium* - **Radium-226**, a decay product of uranium, has a half-life of approximately **1,600 years**. - Although much longer than radon and cesium, it is still orders of magnitude shorter than the half-life of uranium-238.